Effects of experimental chronic jet lag on hematological and immune parameters in mice

Abstract

It has been demonstrated that circadian disruption can cause elevated risk of a variety of health problems. However, the molecular mechanisms are still not clear. The objective of this study was to investigate the effects of circadian disruption on host immunity. In this study, we used a chronic jet lag model to induce circadian disruption in mice, specifically by advancing light onset eight hours in every 48 hours. Peripheral hematologic parameters and immune parameters were measured and analyzed by two-way ANOVA and cosinor analysis. It was found that the chronic jet lag changed the rhythmic profiles of peripheral lymphocytes and the helper subset of T lymphocytes in the spleen. Furthermore, rhythmic profile of Con A-induced splenocyte proliferation was altered. In addition, it was found that experimental chronic jet lag can increase IL-6 plasma levels. Our findings demonstrate that circadian disruption can affect host immunity, suggesting that circadian disruption can induce inflammatory responses and promote carcinogenesis or tumor progression.

Keywords:

• circadian disruption
• cytokine
• interleukin-6
• circadian rhythm
• mouse

Acknowledgements

We thank Dr Li XM and Dr F. Lévi (INSERM U776, France) for helpful discussions; Dr Zhang XM (BD™ Biosciences, USA) for technical assistance. This work was supported by the National Natural Science Foundation of China (No. 30500589), and by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, PR China (2005).